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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 16 |
| 4 | 137 |
| 5 | 1536 |
| 6 | 22417 |
| 7 | 407884 |
| 8 | 8920641 |
| 9 | 230576320 |
| 10 | 6928080641 |
| 11 | 238375169484 |
| 12 | 9288784476193 |
| 13 | 406150114297552 |
| 14 | 19761959813464065 |
| 15 | 1062437048084297596 |
| 16 | 62727815353861478273 |
| 17 | 4045278841893314992896 |
[1,1,3,16,137,1536,22417,407884,8920641,230576320, 6928080641,238375169484,9288784476193, 406150114297552,19761959813464065, 1062437048084297596,62727815353861478273, 4045278841893314992896] |